A polishing apparatus represented by a chemical mechanical polishing (CMP) apparatus polishes a substrate surface by relatively moving both of a polishing pad and the substrate surface to be polished in a contacted state. Consequently, the polishing pad is gradually worn away, and fine roughness on a surface of the polishing pad is crushed, which may decrease a polishing rate. Therefore, the fine roughness needs to be reformed on the polishing pad surface by dressing the polishing pad surface by a dresser in which a plurality of diamond particles is electrically deposited on a surface and a dresser having a brush on a surface (for example, JP 9-300207 A and JP 2010-76049 A).
Conventionally, dressing is usually performed by using a dresser having a size which can cover a whole polishing pad (for example, JP 9-300207 A). However, in recent years, a substrate is increased in size, and to prevent a related increase in size of a polishing apparatus to the extent possible, a small-sized dresser is used (for example JP 2010-76049 A). In the case where a dresser is smaller than a polishing pad, there is a problem that it is difficult to uniform the polishing pad.
Therefore, it is desirable to provide a polishing apparatus capable of uniforming a polishing pad by a small dresser, a method for controlling the same, and a dressing condition output method.
According to one embodiment, a polishing apparatus includes: a turntable for supporting a polishing pad; a turntable rotation mechanism configured to rotate the turntable; a dresser configured to dress the polishing pad; and a scanning mechanism configured to cause the dresser to scan between a first position and a second position on the polishing pad, wherein Ttt/Tds and Tds/Ttt are a non-integer where the Ttt is a rotation cycle of the turntable during dressing, and the Tds is a scanning cycle during which the dresser scans between the first position and the second position.
According to another embodiment, a polishing apparatus including: a turntable for supporting a polishing pad; a turntable rotation mechanism configured to rotate the turntable; a dresser configured to dress the polishing pad; a pressing mechanism configured to press the dresser against the polishing pad; and a scanning mechanism configured the dresser to scan between a first position and a second position of the polishing pad, wherein V(t)A(t)/r(t) is substantially constant where the V(t) is a relative speed between the dresser and the polishing pad at a time t, the r(t) is a distance between a center of the turntable and a center of the dresser at a time t, and the A(t) is a pressing force or a pressure of the dresser against the polishing pad at a time t.
According to another embodiment, a control method for a polishing apparatus, the method including: providing a turntable for supporting a polishing pad, a turntable rotation mechanism, a dresser, a scanning mechanism, and a controller; and controlling the turntable rotation mechanism and the scanning mechanism such that Ttt/Tds and Tds/Ttt become non-integers in a case where a rotation cycle of the turntable during dressing is denoted by Ttt, and a scanning cycle in which the dresser scans between a first position and a second position on the polishing pad is denoted by Tds.
According to another embodiment, a control method for a polishing apparatus, the method including: providing a turntable for supporting a polishing pad, a turntable rotation mechanism, a dresser, a pressing mechanism, a scanning mechanism, and a controller; and controlling the turntable rotation mechanism, the pressing mechanism, and the scanning mechanism such that V(t)A(t)/r(t) becomes substantially constant where the V(t) is a relative speed between the dresser and the polishing pad at a time t, the r(t) is a distance between a center of the turntable and a center of the dresser at a time t, and the A(t) is a pressing force or a pressure of the dresser against the polishing pad at a time t.
According to another embodiment, a dressing condition output method for a polishing apparatus, the method including: preparing a turntable for supporting a polishing pad, a turntable rotation mechanism a dresser, a scanning mechanism, and a controller; receiving a restriction condition; first referring to a database previously storing a first condition which is a dressing condition capable of uniformly dressing the polishing pad and a second condition which is a dressing condition incapable of uniformly dressing the polishing pad, and outputting the first condition in a case where the first condition satisfying the restriction condition is stored in the database; calculating a dressing condition in a case where the first condition satisfying the restriction condition is not stored; and second referring to the database to output the calculated dressing condition in a case where the calculated dressing condition and the second condition are not matched, wherein, upon calculating the dressing condition, the dressing condition is calculated such that Ttt/Tds and Tds/Ttt become non-integers where the Ttt is a rotation cycle of the turntable during dressing, and the Tds is a scanning cycle during which the dresser scans between a first position and a second position on the polishing pad.
According to another embodiment, a method for outputting a dressing condition for a polishing apparatus, the method including: supplying a turntable for supporting a polishing pad, a turntable rotation mechanism, a dresser, a pressing mechanism, a scanning mechanism, and a controller; and receiving a restriction condition; first referring to a database preliminary storing the first condition which is a dressing condition capable of uniformly dressing the polishing pad and a second condition which is a dressing condition incapable of uniformly dressing the polishing pad, and outputting a first condition in a case where the first condition satisfying the control condition is stored in the database; calculating a dressing condition in a case where the first condition satisfying the restriction condition is not stored; and second referring to the database to output the calculated dressing condition in a case where the calculated dressing condition and the second condition are not matched, wherein, upon calculating the dressing condition, the dressing condition is calculated such that V(t)A(t)/r(t) becomes substantially constant where the V(t) is a relative speed between the dresser and the polishing pad at a time t, the r(t) is a distance between a center of the turntable and a center of the dresser at a time t, and the A(t) is a pressing force or a pressure of the dresser against the polishing pad at a time t.